The present invention relates to breathing equipment and more particularly to an emergency escape device particularly useful for persons desiring to escape from a hostile environment such as a smoke-filled or burning building.
Many situations unexpectedly arise which thrust a person into an emergency situation wherein the ambient air is unbreathable. A typical situation occurs in a smoke-filled or burning building where fire, heavy smoke and other noxious gases may be produced which could trap people therein. Under these conditions, people must evacuate immediately or face suffocation or injury from smoke inhalation. It is therefore desirable to provide an emergency escape device which provides a temporary air supply to the user in a hostile environment.
Various types of emergency escape breathing devices are known which provide protection against hazardous atmospheres. These devices generally comprise a transparent hood that is pulled over the user's head and a pressurized supply of oxygen which is released to the hood. Typical of such escape devices are those found in the following U.S. Pat. Nos. 4,236,514; 4,221,216; 3,762,604; 3,262,407; and 3,080,586. Although such devices all provide emergency breathing support for a person in a hostile environment, there remains a need for an improved device which is more comfortable to the user. In addition, since emergency escape devices must of necessity be lightweight, the air supply of devices which have been developed to date has been limited so that such devices may only be utilized for a relatively short period of time, i.e. 10 to 15 minutes. In certain situations which may be life threatening, such a short term air supply is inadequate. Further, none of the above devices have included any means for recirculating the hood gas to provide extended use.